Terminal construction



1959 c. D. FLANAGAN ETAL 2,912,570.

I TERMINAL CONSTRUCTION 2 Sheets-Sheet 1 Filed June 4, 1956 Roy's lag/74..

Nov. 10, 1959 Filed June 4, 1956 C. D. FLANAGAN ET AL TERMINALCONSTRUCTION 2 Sheets-Sheet 2 Inventors: CharZes fl. Flanagan Roger WHand,

Agg

United States Patent TERMINAL CONSTRUCTiON CharlesDl Flanagan,Attieboro, and Roger W; Hood,

This invention relates'to' an improved terminal construction including aterminal secured to' anothermember such'as a base or' h'ousing member.

Among. the objects of this invention may be noted theprovision'of'a'no'vel construction whereby a termmal' can be fiiredl'yattachedto" another member without the use of back-up means or theapplication of excessive.

forces, the provision of such a construction which is salvable whendisassembled whereby the construction can be taken apart and reassembledwithout destroying or damaging any of its parts; the provision of sucha.con

struction which readily permits repair and adjustment of I itsassociated parts, the provision of such a construction whereby one ormorete'r'minals can be quickly, efii'cie'ntly,

simply and fixedly'cdnnected to' another member with the application ofonlycomparatively light'force's andin volving only a simple bend'b'ymeans of a sirnpl'e' and conventional tool; and the provisionof such aconstruction which, is economicaL. novel'and' easy to' manufacture,assemble and disassemble. I

Further objects will become a'pparentas the description proceeds.

V The invention accordingly comprises the elements and combinations ofelements, features of construction, and

arrangements of parts which will be exemplified in the structureshereinafter described, and the scope of the application of which will beindicated in the following claims.

In the accompanying drawings, I various possible embodiments of theinvention are illustrated:

Fig. 1 is a fragmentary perspective view of a base or housing member,which forms partof the novel construction according. to. one embodimentof the invention;

Fig. 2 is a fragmentary perspective view of a pair of terminalsfixed-1y" supported on a terminal-carrying member which alsoform part ofthe novel construction according to this embodiment;

Fig. 3' is a fragmentary perspective view of the parts shown in Figs. 1and'2', respectively, theseparts' being shown inlassembl'ed relation; II

Fig.' 4 is a view similar to' Fig. 3 but showing the parts securedtogether according to this invention; v

Fig. 5 is a fragmentary sectional view taken along line 5f5 in Fig} 3; V

Fig. 6 is a fragmentary sectional view taken along line resin F Fig. 7is'a view similar'toFi'g. 6 but showing a portion of the terminalsecured to the'base member according to one process; I

Fig. 8 is a view' similar to Fig. 6 but showing a free end portion ofth'e terminal in its deformed position at h the terminal is securedtothe base. member accord- I 0 another process; I I, Fig. 9 is anelevational viewpartly in. sectionof' a terminal in assembled relationwith a portion of a bas'e member according to another er'nbodiment ofthis invention;

in which several: of

2,912,670 Patented Nov, 10, 1 9,

Fig: 10is a'view similar to Fig; 9' bu t;sh'owing theparts in securedrelation according toione process; I

Fig. 11 is a; viewpartly inrsectio'nf taken 'along line 11-41 in'Fig;10; i v

Figs. 12'and 1'4, respectively, are elevational view s of two otheralternative terminal structures which fallv within the scope of. myinvention; and Figs. 13 and 15 are elevational views partiallyin section.talgen; from the right-. handside of'Figs. 12 :and 14, respectively.

Similar reference characters indicate corresponding,

parts throughout the several views offthedrawings,

The word terminal ispintended"throughout this specification to mean anycurrent conducting prong;

I Referringto Fig: 1, ahollowbase or base member 10 is shown to which itis'frequentlydesirable to secureone or more terminalsforfthe'purpose. ofelectrically com; municatingbetween the'interiorland' exterior of thebase. member. Twoterrninals .11 which come within the scope of theinvention are? shown in Fig, .2; These terminals may be secured'in anyappropriate manner to. a common terminal carrier '12 as; shown in Fig,2. By way of example,,terminal carrier 12 may. combine with terminals11, 1'1 and additional" components (not shown). to forrn an insert13'for an electrical switch, Since the operating mechanism of the'switch. forms no part of theinvention,

this I specification. will not be unnecessarily; complicated by adetailed'description thereof. H

' Ba semember 10 provides an exterior surface 14, to which agu'ideway;or aperture 15 opens-from, the interior. of the base memberi. Adjacenteaclr of guideways. 15 is a' surface portiorr.16"whichmayappropriatelybetermed a reaction surface. Surface portion 16 may be, provided asshown in the drawing the inclined bottom of. a rectangular groove orchannel; I

Each of terminals 11 includes a free-(end. portion. 1'1 which may beprovided wither; aperture 18 for. the. con: nection of,that terminaltojan electrical lead or. the like. The'f ree end -portion 17 of'ea chof terminals 11' provides a substantially U-shaped slot '19 to form acantilever member or'l'ug 20'." Cantilever'lug 2g is therefore integralat one end with terminal end. portion, 117iand extends; to its free endalongthe plane-ofthe remainderofterminal portion 17 Thewidth of theU-shaped' slot may from a somewhat, comparatively larger Width than:that shown in Fig. 5} to the extent that: it comprises a. mere. slit.

Beforedescribing the methods by which each: of terminals 1 1 along with.terminal carrier 12 is secured or affixed' with respect to base member10', it mightibe well to' 'expl'ain that each of terminals 11 iscomposed'offa suitably bendable, electrically conductive material. suchas Monel, brass, orcopper. Base member 10 may be formed of a suitableelectrically insulating material. such as the customary molded plastics,ceramics,,etc-

In assembling insert 13, with base member 10, the insert is aligned withthe hollow portion of the, housing and. moved thereinto to bring thefree end portion 1.7 of each of terminals 1-1, 11 to the outwardlyprojecting position shown in Figs. 3, Sand 6. It will be noted-thatlongi tudinal movement of each of terminals II, in its direction ofinsertion is limited by the engagement of surface 21 of member 12 withinterior surface 2210f base member 10. Although the fit of each ofterminals 11 in its respec tive guideway15 may be relatively loose,eachtermin'alis substantially confined by that guideway and/orthe'interfitting surfaces of base member10 and insert13 fonlongi tudinalmovement; r p

The terminals-ofthis invention can now be secured to their respectivebase member by either of two preferred 1 methods-Which will be describedbelow. '7

identical with the other, and since each terminal is or may be securedto its respective base independently of the other, a detaileddescription of the methods of securing only one of the terminals to base10, after assembly therewith, will suffice for both.

With a terminal 11 in its fully inserted position with respect to basemember 10 as shown in Figs. 3, 5 and 6, it will be noted that theextreme free end surface 23 of cantiliver lug 20 has been moved slightlypast the innermost edge of reaction surface 16.

To secure terminal 11 with respect to base member 10, free end portion17 of terminal 11 is deformed to the left as viewed in Fig. 6 tosubstantially the position shown in Fig. 8. Although it is notnecessary, an auxiliary block or tool 24 may be positioned as indicatedin dotted lines in Fig. 8 against which the terminal may be deformed.Either of these alternatives would prevent a stress concentration in thematerial of the base such as would occur were the terminal deformedagainst corner 25 of the base member. The zone within which the terminalis transversely deformed must be within one extremity defined by thefree end of cantiliver lug 20 and another extremity at or closelyadjacent the fixed end of cantilever lug 20. Since the effectivedeformable width of the terminal 11 at this zone is obviously limited tothose portions of the terminal between each of its side edges and theedge of U-shaped slot 19 adjacent thereto, it is apparent that theterminal is more readily deformable at this zone than at other sectionsalong the terminal.

During this deforming step, cantilever lug 20 swings outwardly from theadjacent portion of the terminal to bring the free end of lug 20 intojamming engagement with reaction surface 16 as shown in Figs. 4 and 8.The angle which reaction surface 16 forms with the axis of guideway 15is such that once the free end of lug 20 first engages the reactionsurface, continued swinging movement of the lug continually increasesthe jamming effect between the lug and the reaction surface. Moreparticularly, during swinging movement of the lug 20, the tangent of thecurve traced by the free end of the lug forms, at the intersection ofthis curve with the reaction surface, a substantially greater angle withthe axis of the guideway than that formed by the reaction surface withthe axis of the guideway.

The result of this jamming effect between lug 20 and reaction surface 16is to draw or force stop surface 21 of member 12 against surface 22 ofbase 10. The greater the jamming effect, the greater the force will bewith which surfaces 21 and 22 are drawn or forced together. Accordingly,with the free end of lug 20 jammed against reaction surface 16, surface21 is maintained tightly against surface 22. and the terminal iseffectively secured to base member 10. In fact, the fit of the parts canbe such with this arrangement, so that substantially no movement,lateral or otherwise, of the terminal with respect to the base orhousing will ensue during even hard usage under adverse conditions.

It will be noted that, within the above-defined deformable zone of theterminal, the closer the line of deformation of the terminal occurs tothe fixed end of the lug, the farther the lug will swing outwardly fromthe adjacent portion of the terminal and the greater will be the jammingeffect. Depending upon the length of the lug 20, the dimensionaltolerances of the parts, the jamming force required and the proximity ofthe line of deformation of the terminal to the fixed end of the lug, itis well within the purview of one with only ordinary skill in the art tovary the angle which the reaction surface forms with the axis of theguideway for optimum results. According to one construction of a formsimilar to that shown in Figs. 1-6 and 8, the reaction surface isdisposed at an angle of 45 with respect to the axis of the guideway, thelug has a length of .187 inch from its free end to its fixed end, andthe smallest allowable dimensional tolerance for any of the parts is setat .002 inch. W h

these dimensions and this tolerance, the jamming effect is suificient tosecure the parts together so as to prevent any movement of the terminalwith respect to the base member.

It should be particularly noted that during the abovedescribeddeformation step, the forces exerted on the terminal always tend to drawor force stop surface 21 of member 12 against surface 22 of base 10while jamming lug 20 against reaction surface 16. These effects are inopposition to each other and the result is that no back-up means isrequired to secure the parts of this improved construction together, incontradistinction to the requirements of conventional constructions. Theterm back-up means, as used throughout this specification, refers tosuch means as might be used to hold the parts of the constructiontogether while they are being secured.

Frequently it is desired that the interior of the housing be closed offor isolated from the circumambient atmosphere, in which case a suitablesealant may be applied about the opening in surface 14 formed byguideway 15 and reaction surface 16, and against the adjacent sur facesof terminal 11. In this regard, a sealant which is frangible aftersetting or otherwise expendable may be utilized such that if theassembly should subsequently be disassembled, the sealant could beforcibly removed without concomitant damage or injury to any of theparts of the assembly.

It will be clear that this improved construction permits terminals 11 tobe disassembled from the base 10 by the simple expedient of forcingterminal portions 11 back to. the relatively straight conformation shownin Fig. 5. Such movement is effective to swing the free end of lug 20away from reaction surface 16 whereby the terminals can be withdrawnfrom the base. Since this construction is so readily manipulable fordisassembly purposes, it is obvious that repair and/or adjustment of theconstruction and its associated parts can be quickly and efficientlycarried out. It is also to be noted that the allowable dimensionaltolerances for the parts of this construction are ordinarily well withinthe range of modern mass-production control.

To deform the terminal as described above, a conventional pair ofpliers, with or without tool 24, may be used thus rendering the parts ofthis improved construction capable of being effectively secured in thefield. or at its location of operation. It will be readily recognized bythose with only ordinary skill in the art that, in mass production, asimple reciprocable press having a bending die would be effective, withor without tool 24, to carry out the above-described deforming step.

Another method of securing the terminal and the base member of theconstruction shown in Figs. 1-3, 5 and 6 may be used. With the terminal11 in its fully inserted position as best shown in Figs. 3, 5 and 6, aforce may be applied by an appropriate tool (see Fig. 7) against lug 20,to deform the lug to bring its free end 23 into jamming engagement withreaction surface 16 as shown in Fig. 7. The effect is to force surface21 of carrier 12 tightly against surface 22. of base 10 whereby terminal11 is effectively secured to base 10. It is sometimes desirable to placea reinforcing member against the oppo site side of the terminal fromthat at which the lugdeforming tool is applied to prevent unintendeddeforma tion of the terminal during the lug-deforming step.

During application of the deforming force according to this alternativesecuring method, surfaces 21 and 22 are always forced together and it istherefore clear that, as with the previously described securing method,no back-up means is required during the securing operation. Oneapplication when this alternative securing method is advantageous ariseswhen it is required or desired that the outwardly projecting portion ofthe terminal be sub stantially straight.

The angular relationship between the axis of the guideway and thereaction surface for this securing method sis-12,676

will, of course, be substantially the same as and will be determined bythe same factors as those stated above with. respect to thefirst-described securing method.

Among other advantages provided by this alternative securing method andbesides obviating the use of back-up means during the securingoperation, many of the other advantages ascribed above with respect tothe first-described" securing method are provided. That is, a suitablesealant may be applied as described above; the terminal is readilyseparated from the base member (by merely deforming the free end of lug20 back within the confines of the remainder of the terminal) Withoutdamaging either the terminal or the base member such as to militateagainstre-use of these parts; repair and/or adjustment of theconstruction and its associated parts can be quickly and e'fiicientlycarried out; a simple tool may be used to effect the deforming stepwhereby the parts of this construction can be effectively securedtogether in the field or at its location of operation; and the dimensional tolerances of the parts are well within the range ofmass-production control.

Figs. 9-11 illustrate another constructional embodiment falling withinthe scope of the invention. In this embodiment the base member is in theform of asubstantially flat plate or block 27. Base member 27 iscomposed of a suitable electrically insulating material such as thecustomary molded plastics, ceramics, etc., and is provided with aguideway or aperture 28 and reaction surface 29 which are substantiallyidentical in structure and functionto guideway and reaction surface 16,respectively, of the constructional embodiment shown in Figs. 1-8.

The embodiment shown in Figs. 9-11 further includes a terminal 30 havinga free end portion 31 which is substantially identical in structure andfunction to free end portion 17 of the embodiment shown in Figs. 1-8.That is, aperture 32, cantilever lug 33 and U-shaped slot 34 in terminal30 are substantially identical in shape and relative arrangement toaperture 18, cantilever lug and 'U-shaped' slot 19, respectively, interminal 11. T erminal 3:0 is composed of a suitably bendable,electrically conductive'material such, for example, as Monel, brass,

or copper.

The embodiment illustrated in Figs. 91l demonstrates to some extent thewide variation of the particular forms this improved construction mayassume. In this embodiment the means for limiting the extent ofinsertion cr-extent of longitudinal movement of the terminal in onedirection is the surface 35 which is properly disposed when the terminalis bent at 36 and return bent at 37. With terminal 30 fully inserted asshown in Fig. 9', free end portion 31 is then deformed to the left asviewed in Fig. 9 to the position shown in Fig. 10 and in the mannerdescribed above with respect to Fig. 8. With free end portion 31 sodeformed, free end surface 39 of lug 33 is jammed against reactionsurface 29 as shown in Figs. 10 and 11. The result, as with theembodiment illustrated in Figs. l-6 and 8, is that surface 35 ofterminal 30 is drawn or'forced tightly against the adjacent surface ofbase 27 whereby terminal 30 is effectively secured to base 27. Not onlycan the parts of the corn struction shown in Figs. 10 and 11 bedisassembled with out such damage thereto as would militate againstreassembling and securing the same parts, but all of the otheradvantages ascribed above with respect to the embodiment and securingmethod shown in Figs. 1-6 and 8 apply as well to the embodiment shown inFigs. 9-1l.

It will be obvious that many different forms ofstop means may beprovidedin fixed relation to' the terminal to limit the extent of itsinsertion along the base mem' ber. Fig: 12 illustrates one of these manyforms in that the terminal 41 is provided with a pair of extensions orprojections 42, 42", each of which provides a shoulder 43 forcooperation with an appropriate portion of the base member to limit theextent of movement of the terminal in one direction with respect to thebase member.

Figs; 12 and 13-, and Figs. 14 and 15, respectively, il"

lustrate two other forms in which the cantilever lug may between twotransverse extremities one of which is coex tensive with the free end ofthe cantilever lug and the other of which is coextensive with the fixedend; of the cantilever lug. A terminal of the form shown in Figs. 12 and13 is of great'advantage when a greater currentcarrying capacity of theterminal is needed. Obviously, with everything else being equal, thecurrent-carrying capacity of terminal 41 which has no slotted portionadjacent the cantilever lug will be greater than that, for example, ofthe terminals shown in Figs. 1 8 and Figs. 9 11, respectively.

The alternative terminal structure illustrated in Figs. 14 and 15 issimilar to that of Figs. 12 and 13 in that a separately formedcantilever lug 48 is secured at its one end to terminal 47 by a weld 49or its equivalent. The structure of terminal 47 is different from thatof ter minal 41 in that an aperture is provided thereby adjacentcantilever lug 48 at the deformable zone. A terminal having the formshown in Figs. 14 and 15 has the advantage, as does a terminal of theform shown in Figs. 1-8 and Figs. 9-11, respectively, of being morereadily deformable at the deformable zone than a terminal such as thatshown in Figs. 12 and 13. This feature becomes advantageous when thecurrent-carrying capacity of the terminal need not be so great and theparticular material of wlhlich the terminal is composed is not readilydeforma e.

It will be understood that any one of the cantilever lug structuresdisclosed herein may be utilized with any one of the stop meansarrangements disclosed herein, and vice versa. For example, the stopmeans comprising proections 42, 42 shown integral with terminal 41 inFig. 12 could be eliminated therefrom and this terminal could then bemounted on a terminal carrier which provides stop means as in theembodiment shown in Figs. 1-8.

As many changes could be made in the above construction and arrangementsof parts without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustratrve and notin a limiting sense.

We claim:

1. In combination, a base member, and an electrically conductiveterminal, said base member providing a guideway, an exterior surface anda reaction surface, one end of said guideway terminating at saidexterior surface, said reaction surface diverging from said guidewaytoward said exterior surface at an angle to said guideway, said terminallying in said guideway and having a portion projectingoutwardly fromsaid base member and past said exterior surface, said terminal carryingstop means abutting said base member to prevent movement of the terminalin one direction along said guideway, said terminal carrying a lughaving a free end'and adapted to be bent to swing said free end in anare, said free end of the lug when bent being jammed against saidreaction surface to prevent movement of the terminal in the oppositedirection along said guideway, the tangent of said are at the point ofjamming making an angle with said guideway not less than the said angleof said reaction surface.

2. In combination, a base member providing a guideway extendingtherethrough, said base member having an exterior surface, one end ofsaid guideWay opening to said exterior surface, an electricallyconductive terminal having a first portion disposed in said guideway anda second portion projecting outwardly from said first por tion and pastsaid exterior surface, means carried by said terminal and abutting aportion of said base member tc prevent movement of said terminal in onedirection along said guideway, and means to prevent movement of saidterminal in the opposite direction along said guideway, said last-namedmeans including a reaction surface pro vided by said base member and, insaid first direction, diverging from said guideway to said exteriorsurface at an angle to said guideway, and said last-named means furtherincluding a lug carried by the projecting portion of said terminal, saidlug having a free end portion and adapted to be bent to swing said freeend portion in an are, said lug, when bent, being disposed in jammedengagement with said reaction surface to press said firstnamed meanstightly against said base member portion and thereby secure the terminalto the base member, the tangent of said are at the point of jammingmaking an angle with said guideway not less than the said angle of saidreaction surface.

3. An electrical switch construction comprising a hollow base memberproviding an external surface and a guideway opening to said surfacefrom the interior of the base member, said base member further providinga reaction surface extending between said external surface and saidguideway, said reaction surface being angularly disposed relative tosaid' guideway; an insert for said base member including an electricallyconductive terminal having a portion projecting through said guideway,said insert further including a terminal carrier fixedly secured withrespect to said terminal and having a surface in engagement with saidbase member to limit movement of the insert along the base member in onedirection, said portion of the terminal including a lug, the free end ofsaid lug being adapted to be bent to swing said lug in an are; said lug,when bent, being disposed in jammed engagement against said reactionsurface whereby said terminal carrier surface is pressed against thebase member to secure the terminal with respect to the base member, thetangent of said are, at the point of jamming, making an angle with saidguideway not less than the angle of said reaction surface.

References Cited in the file of this patent UNITED STATES PATENTS2,312,795 Brownstein Mar. 2, 1943 2,537,820 Flood Ian. 9, 1951 2,579,841Ludwig Dec. 25, 1951 FOREIGN PATENTS 149,753 Australia Ian. 29, 1953

